The primary objective of the Tissue Culture CORE is to provide pure populations of human keratinocytes, melanocytes, or fibroblasts cultured from normal neonatal or adult skin for dermatologic research studies. Other objectives of the tissue culture CORE are to provide specialized tissue culture services as needed to support Pilot and Feasibility projects, to give advice and training concerning the culturing of keratinocytes, melanocytes and fibroblasts and to provide tissue culture facilities to new or established investigators who do not have access to such facilities. Hence, the five major goals of this CORE are to: 1.Provide frozen stocks of primary or low passage cultures of normal human keratinocytes, melanocytes and fibroblasts which are suitable for subculture and expansion into populations for study. The cell stocks will be initiated from neonatal foreskins and from routine excess adult skin samples and will be cataloged according to donor site, age, sex and race along with the culture passage number. 2. Provide subcultures of keratinocytes, melanocytes or fibroblasts ready for direct study, rather than the frozen stocks suitable for subculturing. This service is provided in support of all Pilot and Feasibility Projects as well as to accommodate other investigators who do not have access to a tissue culture facility or the time and experience to initiate and propagate subcultures. It is anticipated that the major part of providing cells ready for direct study will include tailoring culture conditions to the needs of a particular experiment. For example the Tissue Culture CORE will when needed provide cells: at different culture densities; growing for specified times with or without added cytokines or growth factors; actively growing or serum-starved and quiescent; growing for specified times on dishes coated with different extracellular matrix components; at high versus low calcium concentrations to allow or prevent keratinocyte differentiation, respectively. 3. Provide specific and unique tissue culture services in support of individual Pilot and Feasibility projects. In support of current Pilot and Feasibility Projects, it is anticipated that the Tissue Culture CORE will: store and culture immortalized cell lines; set up living skin equivalents; culture other human cells for genetic analysis; culture cells on glass slides; initiate cells into culture for limited times and culture skin explants on collagen gels. 4. Provide use of tissue culture facility for experiments which require sterile techniques and prolonged incubations. Mechanical wounding of cultures and monitoring of cell migration and proliferation to repair the wound is one potential example of such a use of the Tissue Culture CORE facilities. 5. Provide training in the initiation and subculturing of keratinocytes, fibroblasts and melanocytes.